Power transistors commonly employed in automotive and industrial electronics require a low area-specific on-resistance (Ron×A) while securing a high voltage blocking capability. For example, a MOS (“metal oxide semiconductor”) power transistor should be capable, depending upon application requirements, to block drain-to-source voltages Vds of some tenths to some hundreds or thousands of volts. MOS power transistors typically conduct very large currents which may be up to some hundreds of amperes at typical gate-source voltages of about 2 to 20 V.
The use of power MOSFETs (“metal oxide semiconductor field effect transistors”) with charge compensation using an isolated field-plate or field-electrode offers an opportunity to reduce the area-specific on-resistance of such a device.
Generally, novel concepts of power MOSFETs which result in improved device characteristics are investigated.
It is particularly an object to provide an improved power MOSFET based on charge compensation using field electrodes which can be shrunk to smaller gate trench widths.